FactoryBot Traits inside Traits

Today I learned you can nest FactoryBot traits within other traits. Traitception?!

Say you have a blog post model with a deleted_at attribute, and an optional deleted_by attribute. You could have:

FactoryBot.define do
  factory :post do
    trait :deleted do
      deleted_at { Time.current }
    end

    trait :deleted_by_admin do
      deleted
      deleted_by { :admin }
    end
  end
end

There the deleted in deleted_by_admin references the deleted trait above it.

You could alternatively define a new factory that composes the two traits, but it's always nice to have options.

factory :admin_deleted_post, traits: [:deleted, :deleted_by_admin]